All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Just Math
Not all are equal (Posted on 2011-12-03) Difficulty: 3 of 5
Given n distinct positive numbers a1,a2,...,an.
We construct all the possible sums (from 1 to n terms).

Prove that among those 2^n-1 sums there are at least n(n+1)/2 different ones.

Source: a problem from Soviet Union 1963 contest

No Solution Yet Submitted by Ady TZIDON    
Rating: 5.0000 (2 votes)

Comments: ( You must be logged in to post comments.)
  Subject Author Date
re(3): Solutionbroll2011-12-08 13:52:12
Some Thoughtsre(2): SolutionAdy TZIDON2011-12-08 13:27:22
re: Solutionbroll2011-12-08 02:13:23
Hints/Tipsre: Solution ok, please editAdy TZIDON2011-12-07 22:57:20
SolutionSolutionJohn Dounis2011-12-07 11:51:59
re(2): possible solutionbroll2011-12-04 10:08:20
re: possible solutionSteve Herman2011-12-04 09:34:30
possible solutionbroll2011-12-04 04:09:59
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (1)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2017 by Animus Pactum Consulting. All rights reserved. Privacy Information